We propose to synthesize model compounds for structural and enzymatic sites in which Cd2+ has replaced Ca2+ or Zn2+. We propose to crystallize these model compounds to determine their crystal structure, to measure the solid state cross polarization magic angle spinning (CP/MAS) and the solution 113Cd NMR. The long term objective of this study is to build a background base for the further utilization of 113Cd NMR in the study of proteins and enzymes, particularly for future developments in which the protein crystal structures are not known and ultimately for the CP/MAS 113Cd NMR study of proteins and enzymes. The short term goal is to make models of the structural and active sites of proteins and enzymes that have been or are currently under study such as carboxypeptidase [CdN200'], carbonic anhydrase, alkaline phosphatase [CdN30] superoxide dismutas [CdN40, CdN30], horse liver alcohol dehydrogenase [CdS4, CdS2NO], metallothionein [Cd3S3, Cd4S4, etc. clusters], parvalbumin [CdOx], conconavalin A [CdOx]. The sulfur ligands to be used in these studies are thiourea, substituted thioureas, dithiocarbamates, thiophenols, malenonitrile thiolates and related ligands. The nitrogen and oxygen bases will be sterically crowded amines, pyridines, imidazoles and various carboxylic acids.